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와이파이는 이 그림을 떠올려라.
모든 사람들이 AP랑 통신하길 원한다.
무선 이더넷은 CSMA/CD 방법을 써도 충돌이 일어날 수 밖에 없다. 그래서 유선 이더넷에선 필요하지 않았던 ACK. 왜냐하면 내가 충돌이 일어나지 않으면 FRAME이 제대로 간거니까 ! 쨌든 와이파이에선 ACK가 필요하다. 그런데 TCP에서 사용한 ACK랑은 완전 다른 개념이다. TCP에서 end-to- end feedback이였다면 와이파이는 link layer ank다 !
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